This invention relates to the production of elastomeric pressurized fluid conveying system hoses and more particularly to a method of producing a pressurized fluid conveying system hose having ends of different diameter. Such hoses are commonly used in automotive vehicles for carrying hydraulic fluid between a pump, a reservoir and an hydraulic device such as a power steering unit. These hoses, commonly called hydraulic hoses, are customarily of uniform internal diameter and are clamped or coupled at each end to a nipple having an external diameter substantially equal to the internal diameter of the hose. This creates a design constraint for the equipment being serviced by the hose. Oftentimes it is desirable to present the hose ends to nipples of different external diameter. This requires an hydraulic hose having ends of different internal diameter. Heretofore there has been no economical way of producing a hose having a reduced diameter on at least one end.
It is known in the prior art to build a hose upon a mandrel in such a way as to produce an end of slightly reduced diameter, as shown, for example, in Greacen U.S. Pat. No. 165,324. However, the Greacen method proceeds by a complicated series of steps involving placement and positioning on the mandrel of a rubber core, a helically coiled, tempered and untempered steel wire and a suitable covering material. It is also known to place a hose upon a mandrel for curing and to wrap the hose with shrink film to compress it against the mandrel, as taught by Borden U.S. Pat. No. 3,752,719. Other prior art, such as Badberg et. al. U.S. Pat. No. 4,171,118, reshapes a cylindrical hose into a hose of complex configuration by vulcanization upon a specially shaped mandrel having at least one end enlarged.